Abstract
Purpose :
There is limited knowledge of normal ocular growth during early childhood. Such information would make an important contribution towards management of childhood conditions such as myopia, cataract and glaucoma. We performed a prospective, cross-sectional, clinical study to measure ocular growth in a large cohort of infants and young children.
Methods :
330 children (aged 7 weeks to 7 years) with no ocular problems, undergoing routine surgery for non-ophthalmic related conditions were recruited. All measurements, carried out by a single clinical researcher, were performed during general anaesthesia and before the operating procedure. Standard, direct corneal aplanation instruments were used to ensure accuracy. Axial length, lens thickness, anterior and vitreous chamber depth measurements were obtained for both eyes of each subject.
Results :
The right eyes of the participants were included in the final analysis. The best fit to the data was obtained using the least-squares method. Several functional models were investigated, including increasing forms of the exponential decay. It was concluded, that the growth of the axial length for ages between 7 weeks to 7 years is best described by the natural logarithm function with two coefficients. The bootstrap method was used to calculate the confidence bounds for the fitted coefficients at 95% confidence level.
The overall ocular growth pattern is characterised by a rapid growth in the first year of life, followed by a steady growth throughout the measured study range. AL increased from 16.63mm (16.24, 17.03mm, 95% CI) to 22.58mm (21.66, 23.45mm) at age 7 years. ACD increased from 2.80mm (2.63, 2.97mm) to 3.58mm (3.26, 3.90mm). VCD increased from 10.41mm (9.92, 10.86mm) to 14.67 (13.73, 15.51mm). LT remained similar at 3.84mm (3.82, 3.88mm) to 3.82mm (3.78, 3.87mm).
Conclusions :
This is the largest dataset and the only study measuring ocular growth using direct methods. We present normal ocular growth measurements and their functional forms. The rapid growth of the eye in early childhood is contributed largely by growth of the vitreous chamber, which mimics the axial length growth pattern. Our measurement of normal ocular growth should be applicable in clinical setting to increase the understanding of impact of childhood ocular conditions on ocular growth.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.